Measles (B05) ICD-10-CM
The B05 code range covers measles with 10 ICD-10-CM diagnosis codes. 8 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- morbilli
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- subacute sclerosing panencephalitis A81.1
Codes in the B05 Range 10 codes · 8 billable
- B05 MeaslesNon-billable
- B05.0 Measles complicated by encephalitis
- B05.1 Measles complicated by meningitis
- B05.2 Measles complicated by pneumonia
- B05.3 Measles complicated by otitis media
- B05.4 Measles with intestinal complications
- B05.8 Measles with other complicationsNon-billable
- B05.81 Measles keratitis and keratoconjunctivitis
- B05.89 Other measles complications
- B05.9 Measles without complication
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the B05 range.
Measles
A highly contagious infectious disease caused by MORBILLIVIRUS, common among children but also seen in the nonimmune of any age, in which the virus enters the respiratory tract via droplet nuclei and multiplies in the epithelial cells, spreading throughout the MONONUCLEAR PHAGOCYTE SYSTEM.
Measles Vaccine
A live attenuated virus vaccine of chick embryo origin, used for routine immunization of children and for immunization of adolescents and adults who have not had measles or been immunized with live measles vaccine and have no serum antibodies against measles. Children are usually immunized with measles-mumps-rubella combination vaccine. (From Dorland, 28th ed)
Measles virus
The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.
Measles-Mumps-Rubella Vaccine
A combined vaccine used to prevent MEASLES; MUMPS; and RUBELLA.
Rubella
An acute infectious disease caused by the RUBELLA VIRUS. The virus enters the respiratory tract via airborne droplet and spreads to the LYMPHATIC SYSTEM.
Rubella virus
The type (and only) species of RUBIVIRUS causing acute infection in humans, primarily children and young adults. Humans are the only natural host. A live, attenuated vaccine is available for prophylaxis.
Rubivirus
A genus of the family TOGAVIRIDAE containing only one recognized species, RUBELLA VIRUS. Transmission is primarily by aerosolization.
Subacute Sclerosing Panencephalitis
A rare, slowly progressive encephalitis caused by chronic infection with the MEASLES VIRUS. The condition occurs primarily in children and young adults, approximately 2-8 years after the initial infection. A gradual decline in intellectual abilities and behavioral alterations are followed by progressive MYOCLONUS; MUSCLE SPASTICITY; SEIZURES; DEMENTIA; autonomic dysfunction; and ATAXIA. DEATH usually occurs 1-3 years after disease onset. Pathologic features include perivascular cuffing, eosinophilic cytoplasmic inclusions, neurophagia, and fibrous gliosis. It is caused by the SSPE virus, which is a defective variant of MEASLES VIRUS. (From Adams et al., Principles of Neurology, 6th ed, pp767-8)
Viral Fusion Proteins
Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and thereby may function in the uptake of the virus by cells.
About the B05 Code Range
The ICD-10 code B05 and its related subcodes are used to classify measles and its various complications. These codes help specify whether the patient has a simple case of measles or one complicated by conditions such as encephalitis, meningitis, pneumonia, or other organ-specific issues.
The main code B05 covers measles in general, while subcodes like B05.0 and B05.1 identify measles complicated by serious brain infections such as encephalitis (also known as post measles encephalitis or measles inclusion body encephalitis) and meningitis. Pneumonia due to measles virus is coded as B05.2 and may appear as giant cell pneumonia. Ear infections following measles are coded under B05.3 (post measles otitis media), and intestinal complications are under B05.4. Other important subcodes include B05.81 for measles keratitis or keratoconjunctivitis (eye infections) and B05.89 for other less common measles complications, like measles myocarditis or rubeola retinopathy. The code B05.9 is used for measles without any complications, which may also be referred to as modified measles or identified by characteristic signs such as Koplik spots. Using these codes properly ensures accurate diagnosis and treatment documentation, especially when differentiating among the various manifestations referred to by terms like "post infectious encephalitis" or "exanthem caused by measles virus."
Questions About This Page
How many billable codes are in the B05 range?
Of the 10 codes in this range, 8 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the B05 range classify?
The range classifies measles. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
